Technologies referred to as “smart cut” and “wafer-bonding” have been utilized to bond monocrystalline silicon materials onto semiconductor substrates. Smart cut technology generally refers to a process in which a material is implanted into a silicon substrate to a particular depth and ultimately utilized to crack the substrate, and wafer bonding technology generally refers to a process in which a first semiconductive substrate is bonded to a second semiconductor substrate.
In particular applications of smart cut and wafer-bonding technology, hydrogen ions (which can be, for example, H+, H2+, D+, D2+) are implanted into a first monocrystalline silicon substrate to a desired depth. The first monocrystalline silicon substrate comprises a silicon dioxide surface, and is bonded to a second monocrystalline substrate through the silicon dioxide surface. Subsequently, the bonded first substrate is subjected to a thermal treatment which causes cleavage along the hydrogen ion implant region to split the first substrate at a pre-defined location. The portion of the first substrate remaining bonded to the second substrate can then be utilized as a silicon-on-insulator (SOI) substrate. An exemplary process is described in U.S. Pat. No. 5,953,622. The SOI substrate is subsequently annealed at a temperature of greater than or equal to 900° C. to strengthen chemical coupling within the second substrate.
The present invention encompasses new applications for smart cut and wafer-bonding technology, and new semiconductor structures which can be created utilizing such applications.